Possible Duplicate: Why couldn’t MAC addresses be used instead of IPv4|6 for networking? If physical address or Mac address is unique why do we need logical addressing? This because the size and format of Mac address or physical address is different and logical address size and format is same (The above quotes are from Forouzan’s DCN book) or is there any other reason to it? Asked by Some1.Kill.The.DJ Basically, so that you can communicate with [...]

My windows laptop is directly connected to 192.168.1.0/24 (wireless lan). I access 10.21.0.0/16 though a router that is connected to both networks. The routing works fine with this configuration. I have a VPN, that connects to 10.0.0.0/8. The VPN network doesn’t actually use any IPs in the 10.21.0.0/16 range. So I should be able to configure my routing table to route all the 10.21.0.0/16 IPs through the wireless lan, and all other 10.0.0.0/8 through the [...]

This is a Canonical Question about IPv4 Subnets How does Subnetting Work, and How do you do it by hand or in your head? Can someone explain both conceptually and with several examples? Server Fault gets lots of subnetting homework questions, so we could use an answer to point them to on Server Fault itself. What is classless routing and why is class-based routing obsolete? If I have a network, how do I figure out [...]

This one’s kind of weird, at least to me. I’ve got MSSQL server 2k5 (STD) installed on Server 2k3 R2 SP2 (on account of some legacy software that doesn’t yet support x64 or Server 2008), using Windows Authentication. It’s configured to accept local or remote connections, over either TCP/IP (2) or Named Pipes (3). (I’ve tried disabling Named Pipes, didn’t help.) I can connect to it remotely from any of our SQL servers, and if [...]

Background One of our clients suffers from an intermittant problem with their internet where it will drop packets when a user downloads a large file (their IT is looking into the problem). I have an application consisting of a Web Server running Windows 2008 R2 IIS7.5, and a client running Windows 7, Chrome which uses a long running XMlHttpRequest to transfer “messages” from the server to the client. The problem. My application should be should [...]

Possible Duplicate: How does Subnetting Work? I’m mainly a programmer. I have no idea beyond some basic theory when it comes to Networking/Administrating. My university feels that we should course at least the basics in Networking and I’m psyched. It’s something incredibly new to me and I’m enjoying the class a lot. Yesterday was my first day and he posed the following question. “Since each C-level network can only have a maximum of 254 IP [...]

Can anyone explain why when I ping 192.168.23.019 it gives me a reply from 192.168.23.17? Then If I ping .23.19 I get a request timed out reply. But I can RDP onto .23.19 These are virtual machines.. Does that make a difference? Asked by Axle As poige hints, 019 is a messed up octal way to say 17. 010 = 8, add 9 to that you get 17. So when you ping .019, you accidentally [...]

I’m trying to “tune” the TCP/IP stack on some Windows Server 2008 machines by following the instructions here: http://www.outsystems.com/NetworkForums/ViewTopic.aspx?TopicId=6956&Topic=How-to-tune-the-TCP%2FIP-stack-for-high-volume-of-web-requests One of the suggestions is to increase the dynamic port range and I’ve tried doing so but it fails: C:\Windows\system32>netsh int ipv4 set dynamicportrange tcp start=32767 num=65535 The parameter is incorrect. My question is: which parameter is incorrect? Asked by Lirik You have to run: netsh int ipv4 set dynamicport tcp start=32765 num=32765 This would set [...]

I need to switch Internet Protocol Version 4 (TCP/IPv4) and Internet Protocol Version 6 (TCP/IPv6) settings for DNS server configuration from “Obtain DNS server address automatically” to hard coded values (for Google’s DNS servers) and back. It’s kind of a hassle to do manually (I need to go to Control Panel-Network and Internet-Network Connections, open Wireless Network Connection 2, then open Properties for the corresponding version, enter the DNS server values, and repeat for the [...]

I have the exactly same problem as here: Windows XP TCP/IP No buffer space available On Windows XP Pro, SP3 if one does an experiment where one tries to open TCP/IP sockets in a loop (bascially, listen port 7000, listen port 7001, etc.) After approx 649 open sockets, one will start getting errors: No buffer space available (maximum connections reached?) I’ve tried to edit the registry as described here http://smallvoid.com/article/winnt-tcpip-max-limit.html I set MaxUserPort = 65534 [...]